| We derive and employ an algorithm for the three-dimensional fluid treatment of ionospheric plasma, including the complete set of electromagnetic fields. Explored are the three-dimensional electric and magnetic fields resulting from current divergence, current flows, and Alfven waves associated with low-latitude plasma irregularity dynamics. We investigate both dynamic and static electromagnetic properties. Simulated are the Alfvenic dynamics generated by low-latitude plasma depletions that map electric fields along Earth's magnetic field lines. The time scales of Alfvenic dynamics to settle into an approximately electrostatic state is on the order of seconds to tens of seconds. Presented are the electrostatic three-dimensional electromagnetic characteristics of the gravitational Rayleigh-Taylor mode. Current divergence resulting from plasma depletions generate a current circulation from the bubble to the E region where transverse conductivity is the greatest. Despite high parallel conductivities along Earth's magnetic field lines, we show that magnetic field lines are not exactly equipotential as often approximated. Simulated diamagnetic currents associated with plasma bubbles produce significant perturbation magnetic field parallel to Earth's magnetic field consistent with Stolle et al. (2006). We find that three dimensional ambipolar electric fields are overestimated by one-dimensional theory. The gravitational Rayleigh-Taylor produces zonal polarization electric fields, while zonal winds can add additional meridional electric fields, resulting in a tilted fields. Observed tilted electromagnetic signatures in nature suggests a prevalence of neutral wind influence on low-latitude plasma irregularities. Given a zonal drift, perturbations of certain zonal wavelength can have polarization electric fields resonate due to Alfven resonance. A bubble upwelling at supersonic speeds is simulated. The bubble developed strong negative and positive meridional magnetic fields on the northern and southern edge, respectively, on the order of 100 nT. |
